Railway traffic controlling apparatus



Nov. 24, 1936. P. H. CRAGO ET AL RAILWAY TRAFFIC CONTROLLING APPARATUS Filed April 24, 1935 H m w M 6 K4 i7 R Q H Z a w B wan Paul H. C!

mm/m

TH EIR ATTORNEY Patented Nov. 24, 1936 PATENT @Etlfih RAILWAY TRAFFIC CONTROLLING APPARATUS Paul H. Crago, Wilkinsburg, and Arthur E. Dodd, Swissvale, Pa., assignors to The Union Switch & Signal Company, Swissvale, Pa, a corporation of Pennsylvania Application April 24, 1935, Serial No. 17,978

11 Claims.

Our invention relates to railway trailic controlling apparatus, and has for an object the provision of apparatus controlled by a car for causing operation of a traffic controlling device when a car passes over a given track section in less than a predetermined time interval.

We will describe two forms of apparatus embodying our invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. l is a diagrammatic view illustrating one form of apparatus embodying our invention. Fig. 2 is a diagrammatic view illustrating a modification of a portion of Fig. l, and also embodying our in- LS vention.

Similar reference characters refer to similar parts in each of the two views.

Referring first to Fig. l, the reference characters 2 and 3 designate the rails of a stretch of railway track designated by the reference character X. The rails of track X are divided into three relatively short track sections IT, 2T and 3T by means of insulated joints 4. A traffic controlling device, here shown as a switch, is 5 cated in section ST and is designated by the reference character 5. Each track section is provided with the usual track circuit including a battery 6 connected across the rails at one end of the section and a track relay designated by the reference character R with a distinguishing prefix connected across the rails at the other end of the section.

The reference characters B and C designate the positive and negative terminals, respectively, of a source of current not shown in the drawing. Associated with relay l'IR is a time measuring mechanism, here shown as two slow pick-up slow-release relays and designated by the reference characters lTP and AITP. The relay IT]? is normally energized and is controlled over a front contact l of relay HR. The relay ITP, therefore, will be energized or deenergized depending upon the condition of relay ITR. The relay AlTP is normally deenergized and is controlled over a back contact 8 of the relay lTP. The relay AlTP, therefore, will be energized when the relay lTP is in its deenergized condition and will be deenergized when the relay lTP is in its energized condition. The manner in which relays ITP and AlTP function for timing purposes will be explained more in detail hereinafter.

It will be noted that the track relay ITR, is normally energized over a stick circuit which includes its own front contact 9. The pick-up circuit for the relay ITR extends from rail 2 over wire it to a front contact ll of relay AI'I'P and thence over wire l2 and the winding of relay lTR to the opposite rail 3. The relay ITR, therefore, may be deenergized when section IT becomes occupied but may be energized when section ET is unoccupied only if relay AtTP is in its energized condition. The relay lTR is controlled in this manner to prevent the possibility of relay lTR becoming momentarily picked up should the distance between trucks on a car he sufiicient to bridge section lT. That is, the release time of relay lTP added to the pick-up time of relay AlTP holds the pick-up circuit for relay lTR, open for a predetermined length of time which will usually be sufficient to maintain relay iTR. in its deenergized condition during the time the front and rear trucks of a long car may be bridging the section lT. As will be explained more in detail hereinafter, the release time of relay l'li? combined with the pick-up time of relay MT? is also employed for timing the speed of cars traversing section ET. The pick-up time of relay lTP added to the release time of relay AlTP maintains the pick-up circuit for relay lTR closed momentarily over front contact ll of relay AlTP, so that when section IT is vacated, relay ITR may attain its energized condition and reclose its stick circuit before its pick-up circuit becomes opened.

The reference character MR designates a locking relay which, as will be explained hereinafter, is effective at times to prevent operation of the switch by the second truck of a car. The relay MR is provided with a pick-up circuit which passes from terminal B through front contact it of relay lTR, back contact M of relay 2TB. and relay MR to terminal C, and with a stick circuit which passes from terminal B through front contact l 5 of relay 3TB, front contact I 6 of relay MR. and relay MB to terminal C. The relay MR, therefore, will be picked up when relay lTR is in its normal energized condition provided that relay 2TB. is in its deenergized condition, and will be maintained in such condition until relay 3TB, is released.

The reference character WR designates a switch control relay which is normally deenergized. The relay WR is provided with a pick-up circuit and a stick circuit. The pickup circuit passes from terminal B through back contact I? of relay ITR, back contact l8 of relay 2TB, back contact ill of relay Al'IP, back contact 20 of relay MR, wire 35, and relay WR to terminal 0. The stick circuit passes from terminal B through front contact H of relay 3TB, front contact 22 of relay WR and relay WR to terminal C. The relay WR, therefore, will be picked up when relays ITR and 2'I'R both become deenergized provided relays AITP and relay MR are both in their normal deenergized condition and will be maintained in such condition until relay STR is released.

As indicated by a dotted line, a motor M is operatively connected with the switch 5 through the medium of a standard switch machine (not 7 shown) to operate the switch to a normal position for directing a car to the track designated by the reference character IQA, or to operate the switch to a reverse position for directing a car to the track IEiB. The operation of the motor M is governed by the switch control relay WR in a customary manner. With relay WR deenergized, the motor is provided with a circuit passing from the terminal B over front contact 23 of the track relay 3TB, back point of contact 24 of relay MR, controller contact 25-46 operated by the motor and closed except when the switch 5 is moved to the full normal position, armature 21, back point of contact 28 of relay WR, and motor field winding 29 to the terminal C. When relay WR is energized over its pick-up circuit hereinbefore described, current flows from the terminal B over front contact 23 of relay 3TR, front point of contact 2 1 of relay WR, armature 2?, controller contact 25-36 operated by the motor and closed except when the switch 5 is moved to the full reverse position, front point of contact 28 of relay WR, and motor field winding 29 to the terminal C. The flow of current in armature 2? when relay WR is energized is such as to cause the motor M to rotate in a direction for operating the switch 5 to its reverse position, whereas the flow of current in armature 2'! when relay WR is deenergized is such as to cause the motor M to rotate in a direction for operating the switch 5 to its normal position. It follows that with relay WR deenergized the switch 5 is set to direct a car to the track IEBA, and with relay WR picked up the switch is set to direct a car to the track IGB.

A car entering the track section IT will release the track relay ITR which will in turn deenergize relay ITP. At the expiration of a given interval of time relay ITP will become released, thus energizing relay AITP. At the expiration of another given time interval, relay AITP will become picked up. If the speed of the car is slow enough so that relay AITP reaches its energized position before the car enters section ET and releases relay ZTR, then the pick-up circuit for relay WR will become opened by the opening of back contact IQ of relay AiTP and relay WR will remain deenergized. Under this condition, the switch 5 will not be moved and the car will advance over the switch to track IGA. If the speed of the car is high so that it traverses the section IT and enters section 2T before relay AITP becomes picked up, the switch control relay WR will become energized as soon as the car enters section 2T and shunts relay ZTR, the pick-up circuit for relay WR being closed over the back contacts I! and I8 of relays ITR and ZTR, respectively. Under this condition, the motor M will be perated to move the switch to its reverse position and the car will advance over the switch to the track IGB. As the car passes from the section 2T into the section ET, the shunting of track relay -3TR will open the front contact 2.23 in the motor operating circuit so that the switch 5 may not be operated with a car in section 3T even when relay WR returns to its normal deenergized condition due to the opening of its stick circuit by the opening of front contact 2! of relay 3TR. When the car vacates section 3T, the relay 3T will become energized so that the operating circuit for motor M will become closed by the closing of front contact 23 of relay 3TB. Thus, the motor M will be caused to operate the switch to its normal position. To sum up the operation of the apparatus illustrated in Fig. 1, a car traveling through section IT above a predetermined speed will cause switch 5 to be automatically set in a position to advance the car into track IHB, whereas a car moving below such given speed will cause switch 5 to remain in its normal position so that the car will advance into track IilA. At such times as the switch has been reversed to direct the car into the track IOB, the vacating of section 3T will cause the automatic restoration of switch 5 to its normal position.

It will be noted that the timing of the car in section IT is accomplished by the utilization of the release time of relay iTP and the pick-up time of relay AITP. That is, the time required for relay ITP to become released added to the time required for relay AITP to become picked up is used for determining whether the car is traveling above or below a predetermined speed. We have found that the total operating time of two such relays is substantially constant regardless of changes in temperature, and also regardless of changes in battery voltage through the usual range of battery voltage variation. For example, even though an increase in temperature may bring about a corresponding decrease in the release time of relay ITP, this increase in temperature will also cause a corresponding increase in the pick-up time of relay AITP so that the combined operating time of the two relays remains substantially constant. Our invention, therefore, provides a simple and reliable timing means for determining the speed of a car, which means is substantially constant regardless of changes in temperature and battery voltage.

It will be noted that the locking relay MR will be energized when relay ITR becomes energized and relay 2TR becomes deenergized in response to the car departing from section IT and entering section 2'1, and that relay MR will be stuck up as long as section 3T is unoccupied. It will also be noted that when relay MR is energized the pickup circuit for relay WR becomes opened so that with the relay MR energized relay WR may not be energized. The locking relay MR thus prevents the possibility of the switch being caused to move by the second set of trucks of a slow moving car entering section IT if the spacing between the trucks of such car is of sufficient length to bridge section IT. In other words, if relay MR were not provided, there is a possibility that if relay ITR should become energized while the front and rear trucks of a slow moving car were bridging section IT, the pick-up circuit for relay WR may become closed by the releasing of relay AITP. Under this condition, when the rear set of trucks of such a car enters section IT, the pick-up circuit for relay WR may become closed over back contacts I'I, I8 and I9 of relays ITR, Z'IR and AITP, respectively. Since, however, back contact 28 of relay MR is also included in the pick-up circuit for relay WR, this pick-up circuit cannot be closed as long as relay MR is energized, which relay will remain energized until the car enters section 3T.

Many applications for the apparatus of Fig. 1 will naturally suggest themselves to those skilled in the art. For example, at hump or scale tracks,

a car moving on the scale track X at too high a speed to permit weighing and classification of the car will automatically cause switch to be reversed to direct that car to an emergency track IOB where it can be later brought back and again pushed over the scales. Cars moving over the scales slow .enough to be properly weighed and classified will pass over the switch 5 in its normal position and move to the usual classification yard (track WA).

Referring now to Fig. 2, the reference character PB designates a manual device, here shown as a push button, for causing the switch control relay WR to return to its normal deenergized condition after a car has moved over the switch. The push button PB is provided with a normally closed contact 32 which may be substituted for front contact 2| of relay 3TB in the stick circuit for relay WR. The pick-up circuit for relay WR. connects to wire 3! in a manner similar to that just described for the apparatus shown in Fig. 1. Likewise, all other apparatus operates in conjunction with the push button PE in a manner similar to that described for the apparatus illustrated in Fig. 1.

It is readily apparent that the push button PB provides a means for manually opening the stick circuit for relay WR. Relay WR, therefore, may be controlled by an attendant at the switch so that switch 5 may be caused to return to its normal position or to remain in its reverse position after having been caused to assume such position by a passing car.

Although we have herein shown and described 1 only two forms of apparatus embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is:

1. In combination, a stretch of railway track including a railway trafiic controlling device having a first and a second position and normally occupying the first position, operating means for moving said device, a slow release relay having an initial condition and an operated condition, a slow pick-up relay having an initial condition and an operated condition, means efiective to initiate the operation of said slow release relay when a particular section is occupied by a car approaching said device, means effective to initiate the operation of said slow pick-up relay when said slow release relay has completed its operation, control means governed by the slow pick-up relay and eifective to cause the operating means to move the device to its second position if and only if said'slow pick-up relay is in its initial condition when the car enters another particular section, and means governed by the car after having passed the device to control the operating means to automatically move the device back to its first position.

2. In combination, a stretch of railway track including a railway traific controlling device having a first and a second position and normally occupying the first position, operating means for moving said device, a slow release relay having an initial condition and'an operated condition, a slow pick-up relay having an initial condition and an operated condition, means efiective to initiate the operation of said slow release relay when a particular section is occupied by a car approaching said device, means eifective to initiate the operation of said slow pick-up relay when said slow release relay has completed its operation, control means governed by the slow pick-up relay and effective to cause the operating means to move the device to its second position if and only if said slow pick-up relay is in its initial condition when the car enters another particular section, and manually controlled means for causing the operating means to move the device back to its first position after the car has passed over the device.

3. In combination, a stretch of railway track including a railway switch having a first and a second position and normally occupying the first position, operating means for moving the switch, a first track section traveled by a car in approaching the switch, a slow release relay having an initial condition and an operated condition, a slow pick-up relay having an initial condition and an operated condition, means effective to initiate the operation of said slow release relay when said section is occupied by the car, means effective to initiate the operation of said slow pick-up relay when said slow release relay has completed its operation, a second section between said first section and said switch, a track circuit for said second section including a track relay, and control means governed jointly by said slow pick-up relay and said track relay for automatically causing said operating means to move the switch to the second position if the car enters said second section before said slow pick-up relay has completed its operation.

4. In combination, a railway switch, operating means for moving the switch, a first and a second track section traversed by a car in approaching the switch, a slow pick-up relay having an initial condition and an operated conditiommeans for initiating the operation of said slow pick-up relay a predetermined time interval after the car enters said first section, and control means effective to cause the operating means to move the switch if said relay has not completed its operation when the car enters said second track section but ineffective to control the operating means, if said relay has completed its operation when the car enters said second track section.

5. In combination, a railway switch having a first and a second position and normally occupying its first position, operating means for moving the switch, a first and a second track section traversed by a car in approaching the switch, a first and. second track relay one for each section, a normally energized slow-release relay deenergized when said first track relay is released, a normally deenergized slow pick-up relay energized when said slow-release relay is deenergized, control means governed by said first and second track relays and by said slow pick-up relay and effective at times to control the operating means to move the switch to the second position, and other track circuit means responsive to a car moving over said switch for causing said control means to become eifective to cause said operating means to move said switch back to its first position when the car has passed beyond said switch.

6. In combination, a first and a second and a third track section to be successively traversed by acar, a track relay for each section, a railway switch in the third section, a switch control relay for at times causing the operation of said switch in response to a car approaching said switch in the first and second sections, a locking relay effective at times to prevent said switch control relay from becoming effective to cause the operation of said switch, a pick-up circuit for said locking relay including a front contact of the track relay for the first section and a back contact of the track relay for the second section, and a stick circuit for said locking relay including a front contact of the track relay for the third section.

7. In combination, a first and a second and a third track section to be successively traversed by a car, a track relay for each section, a normally energized slow release relay deenergized when the track relay for the first section is released, a normally deenergized slow pick-up relay energized when said slow release relay is deenergized, a switch in the third section, a switch control relay for governing said switch, a pick-up circuit for said switch control relay including a back contact of the track relay for the first section as well as a back contact for the track relay for the second section and a back contact of the slow pickup relay, and a stick circuit for said switch control relay including a front contact of the track relay for the third section.

8. In combination, a stretch of track including a first and a second section to be successively traversed by a car, a stick relay for the first section, a track relay for the second section, one slow pickup slow release relay normally energized but deenergized when said stick relay is released, another slow pick-up slow release relay normally deenergized but energized when said one slow pick-up slow release relay is deenergized, a pickup circuit for said stick relay including the rails of said first section and a. front contact of said other slow pick-up slow release relay, a stick circuit for said stick relay including its own front contact and the rails of said first section, a railway switch in said stretch, and means for operating said switch governed in part by said other slow pick-up slow release relay and by the track relay for the second section.

9. In combination, a slow release relay normally energized, a slow pick-up relay normally deenergized, a circuit for said slow pick-up relay controlled by a back contact of said slow release relay, a railway trafiic controlling device, operating means for moving said device, means for deenergizing said slow release relay when a car approaching said device occupies a given section, and control means governed by the slow pick-up relay eiTective to cause said operating means to move said device if the car traverses such given section in less than a measured time interval.

10. In combination, a timing mechanism including two slow acting relays one relay of which is set into operation when the other relay completes its operation, a railway traffic controlling device having a first and a second position and normally occupying the first position, operating means for moving said device, means for initiating the operation of said other slow acting relay when a car approaching said device occupies a given section, and control means governed by said one slow acting relay for causing the operating means to move the device to the second position or to retain the device in the first position depending upon thecondition of said one slow acting relay when the car enters the next successive section. 11. In combination, a railway switch having a first and a second position, operating means for moving the switch, a normally deenergized switch controlling relay, circuit means controlled by said relay and efiective when the relay is deenergized to cause the operating means to move the switch to the first position and efiective when the relay is energized to cause the operating means to move the switch to the second position, a first track circuit responsive to a car approaching the switch and efiective at times to energize said relay for automatically causing the switch to be moved to the second position, a second track circuit responsive to a car passing over the switch, a stick circuit for said relay controlled by said second track circuit, and other track circuit means responsive to a car moving away from said switch for opening the stick circuit to deenergize said relay and automatically restore the switch to the first position.

PAUL H. CRAGO.

ARTHUR E. DODD. 

